Circuit breaker



Nov. 27, 1934. w. H. FRANK ET AL 1,932,289

CIRCUIT BREAKER Filed Jan. 1933 MMIIIMIMMMN INVENTORS. J, E

ATTORNEY.

Patented Nov. 27, 1934 UNITED STATES CIRCUIT BREAKER William H. FrankMicln, assignors Company, Virginia Application January 3,

6 Claims.

The invention of this application relates to circuit breakers.

A principal object of the invention is to provide, for circuit breakers,novel-forms of holding devices which may be calibrated, as desired bythe operator, to release the circuit breaker at various overloadamperages. More specifically, there are provided holding devicesincluding fulm crumed holding levers connected to thermal warpingelements by variable connections which constitute the calibration means,the connections being varied to vary the effects of the warping elementson the holding elements.v

Still further objects of the invention will be readily apparent to thoseskilled in the art upon reference to the following detailed descriptionof embodiments of the invention, the same to be read in connection withthe appended drawing. Referring to the drawing, it will be seen thatFigs. 1 and 2 are elevation and end views of one form of holding device;

Figs. 3 and 4 are elevation and end views of another form of breakerholding device, shown 5 in On (full lines) and overload 011" (dashlines) positions;

Figs. 5 and 6 are similar views of still another form of breaker holdingdevice;

Figs. 7, 8, and 9 show still another form of holding device in left endview, elevation view, and right end view, respectively. L

In Figures 1 and 2, there is shown a device which consists of a U-shapedthermostatic or bimetallic warping element 263, whose legs are connectedrespectively to a contact element of a breaker and to a line. A bracket264 is rigidly secured to warping element 263 by rivets 265 and isinsulated therefrom. An arm 267 is slidably mounted in an elongated slot268 of bracket 264, 0 being clamped to the latter by a washer 269 and ascrew 271 tapped into arm 267. The other end of am 267 is grooved, at272 so as to receive the edge of a latch 273 pivotally secured at itslower end to foot 274 by rivet 275. The upper end of.

latch 273 is provided with a hook 276 which holds pawl 277 firmly whenthe circuit breaker is in either "On or normal Off position.

Under overload conditions the warping element 263 moves to the right.This motion is transmitted through arm 267 to latch 273, moving hook end276 to release pawl 277.

The different positions of arm 267 in latch 273 vary the throw of latch273' and therefore the device can be calibrated to release at variousoverload amperages, which can be indicated by graduations along asurface of bracket 264.

and Joseph Messing, Detroit, to Bulldog Electric Products Detroit,Mich., a corporation of West 1933. Serial No. 649,988

is pivotally connected to bracket 201 by a pin 205 provided with a lockwasher 206 which maintains arm 204 in any desired position, relative tothe element. A pin 207 on the outer or free end of arm 204, rides freelyin a circular slot 208 of a latch 209 pivotally secured to a foot 211 bya rivet 212. A hook 213 on the upper end of latch 209 holds a breakerpawl 214 firmly when the breaker is in its "On position or in its normalOif" position.

When an overload occurs, the warping element 200 moves to the right.This motion is transmitted through arm 204 to latch 209, moving the hookend thereof to release pawl 214. I

The different angular positions of' arm 204 about pivot 205 vary thethrow of end 213 of latch 209 and therefore the device can be calibratedto release at various overload amperages. To indicate these amperages,latch 209 can he graduated along the edge of elongated slot 208.

For reset, pawl 214 presses downward on end 213 of latch 209 forcing itto the right, when pawl 214 is in normal position, the end of latch 209again snaps back to its normal position.

In Figures5 and 6 there is shown a device which consists of a U-shapedthermostatic or bimetallic warping element 221, whose legs are connectedrespectively to a contact element of a breaker and to a. line. A bracket222 is rigidly secured to warping element 221 by rivets 223, there beinginsulation 224, between the element and the bracket. A sector 225 isrigidly fastened to bracket 222 by rivets 226, and is provided with anarcuate slot 227 in which rides a pin 228 rigidly connected to arm 229,which may be fixedly positioned radially within the liniits of arcuateslot 227 in sector 225. The latter is pivotally connected to latch 231by pin 232 provided with a lock washer 233. Latch 231 is pivotallyconnected at one end to foot 235 by rivet 236 and its other end isprovided with a hook 237' which holds pawl 238 firmly, when the circuitbreaker is in either "On or normal "Oi!" positions.

Under overload conditions, the thermal element 221 moves to the right.This motion is transmitted through arm 229 to latch 231, moving the hookend 237 to release pawl 238.

The difierent angular positions or arm 229 about pivot 232 vary thethrow of end 237 of latch 231 and therefore the device can be calibratedto release the pawl at various overload amperages.- These amperages canbe indicated by graduations along the edge of elongated slot 227 inlatch 225.

For reset, pawl 238 presses downward on end 237 of latch 231 forcing itto the right. When pawl 238 is in normal position, the end of latch 237again snaps back in normal position.

In Figures 7, 8, and 9, there is shown a device which consists of aU-shaped thermostatic or bimetallic warping element 243, whose legs areconnected respectively, to the contact element of a breaker and to aline. An arm 244 of insulation, and doubly grooved on its edges at 245is slidably connected to warping element243 and is rigidly secured to aslidable 246 by rivets 247, being insulated from arm 246 by insulation248. The slidable arm 246 is doubly grooved on its edges to receive thesides of latch 249. slidable arm 246 is tapped to receive adjustingscrew 251 which passes through a hole in the end 252 of latch 249, therebeing a check nut 253 on screw 251, to check against and positivelyposition slidable arm 246 in latch 249. The latter is pivotallyconnected to a. frame part 254 of the breaker by a screw 255, surroundedby spacer 256. The upper end of latch 249 is provided with a hook 257which holds pawl 258 firmly when the circuit breaker is in either On ornormal 011 positions. 1

Under overload conditions the warping element 243 moves to the left.This motion is transmitted through slidable arm 246 to latch 249, movinghook end 257 to release pawl 258.

The different positions or slidable arm 246 vary the throw of latch 249and therefore the device can be calibrated to release at variousoverload amperages. These can be indicated by graduations along asurface of latch 249, substantially as shown.

Now having described various embodiments of the invention, selected byway of example, reference will be had to the appended drawing whichdetermines the scope of the invention, it being understood that, exceptas set out in the claims, the invention is not to be limited to theembodiments disclosed.

We claim:

1. In a controlling device of the character described, latching means inthe nature of a lever,

thermally responsive mean also in the nature of a lever, and afiected bychanges in circuit conditions, and a connection between the meanswhereby the latching means will be released by the effect of suchchanges on the thermally responsive means, the connection being movableso as to vary the leverage ratio of bothof the means so that therelease-causing eflect of such changes on the latching means can bevaried.

2. Ina controlling device of the character described, latching means inthe nature of a lever, thermally responsive means also in the nature ofa lever, and thermally affected by changes in circuit conditions, and aconnection between the means whereby the latching means will be releasedby the efiect of such changes on the thermally responsive'means, theconnection being movable so as to vary the leverage ratio of one of themeans so that the release-causing effect of such changes on the latchingmeans can be varied.

3. In a controlling device of the character described, latching means inthe nature of a lever, thermally responsive means also in the nature ofa lever and thermally affected by changes in circuit conditions, and aconnection between the means whereby the latching means will be re-,leased by the effect of such changes on the thermally responsive means,the connection being movable so as to vary the leverage ratio of thefirst mentioned one of the means so that the release-causing effect ofsuch changes on the.

latching means can be varied.

4. In a controlling device of the character described,'latching means inthe nature of a lever, thermally responsive means also in the nature ofa lever and thermally affected by changes in circuit conditions, and aconnection between the means wherebythe latching means will be releasedby the efiect of such changes on the thermally responsive means, theconnection being movable so as to vary the leverage ratio otthe' secondmentioned one of the means so that the release-causing effect of suchchanges on the latching means can be varied.

5. In a controlling device of the character described, latching means inthe nature of a lever,

thermally responsive means thermally afiected by changes in circuitconditions, and a connection between the means whereby the latchingmeans will be released by the effect of such changes on the thermallyresponsive means, the connection being movable so as to vary theleverage ratio of the holding means so that the release-causing effectof such changes on the latching means will be varied. p

6. In a controlling device of the character described, latching means,thermally responsive means in the nature of a lever and thermallyaffected by changes in circuit conditions, and a connection between themeans whereby the latching means will be released by the effect of suchchanges on the thermally responsive means, the

connection being movable so as to vary the leverage ratio of the secondmentioned means so that the release-causing effect of such changes onthe latching means will be varied.

WILLIAM H. FRANK. JOSEPH MESSING.

